1. Field of the Invention
The present invention is generally directed to a switching system and more specifically to a method and circuit apparatus for a switching system.
2. Description of the Related Art
A switching system for the private domain is already known from the product brochure of Siemens AG "HICOM 300 System Product Data", Order No. A 19 100 K 3161-G430X7600. For example, the known switching system allows an expansion up to 5120 ports (page 6 of the product brochure) and enables both a linking to public as well as to private networks (page 56 of the product brochure). Also, the known switching system can be coupled to what is known as a local area network (LAN).
Call number information that has up to 6 call number digit information can be allocated to the internal terminal equipment (page 22 of the product brochure: "Flexible Station Numbering"). The switching-oriented program of the known switching system is thus designed for processing call number information that has a maximum of 6 call number digit information. The known, private switching system thus enables the use of call numbers having exactly as many places as prescribed in standardized, international call number plans for the through-connection of public networks to private branch exchanges. Due to the maximum number of terminal equipment possibly used, there is no need in private branch exchanges for call numbers having more than 6 places. A subsequent expansion of the control software of such a private branch exchange to call numbers having more than 6 places also entails an extraordinarily great amount of work and cost outlay when the call number/selection code interpretation occurs in many switching-oriented situations upon call setup and upon performance feature activation.
British Patent Application GB 2009 564 A (corresponding to German Published Application 27 54 325) discloses a circuit arrangement for abbreviated dialing in a telecommunication switching system, particularly a telephone switching system. In the known circuit arrangement, indicator information to the main memory area for allocated call numbers from the address converter are supplied with the assistance of an abbreviated dialing signal dependent on the switching network chain address of the subscriber line of the calling subscriber. The indicator information is delivered from the appertaining main memory area to the called subscriber location for further use by using this address converter upon utilization of the call number dialed. Each of the appertaining subscriber stations has a main memory area in an abbreviated dialing memory for a call number of subscriber locations reachable by abbreviated dialing. The known circuit arrangement enables the storing of call numbers having a maximum of 12 digits and also enables traffic discrimination digits. However, measures for an expansion of call numbers to a plurality of digits beyond this are not provided in the known circuit arrangement.